xref: /linux/sound/usb/stream.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
1 /*
2  *   This program is free software; you can redistribute it and/or modify
3  *   it under the terms of the GNU General Public License as published by
4  *   the Free Software Foundation; either version 2 of the License, or
5  *   (at your option) any later version.
6  *
7  *   This program is distributed in the hope that it will be useful,
8  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
9  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
10  *   GNU General Public License for more details.
11  *
12  *   You should have received a copy of the GNU General Public License
13  *   along with this program; if not, write to the Free Software
14  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
15  */
16 
17 
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/usb.h>
21 #include <linux/usb/audio.h>
22 #include <linux/usb/audio-v2.h>
23 #include <linux/usb/audio-v3.h>
24 
25 #include <sound/core.h>
26 #include <sound/pcm.h>
27 #include <sound/control.h>
28 #include <sound/tlv.h>
29 
30 #include "usbaudio.h"
31 #include "card.h"
32 #include "proc.h"
33 #include "quirks.h"
34 #include "endpoint.h"
35 #include "pcm.h"
36 #include "helper.h"
37 #include "format.h"
38 #include "clock.h"
39 #include "stream.h"
40 
41 /*
42  * free a substream
43  */
44 static void free_substream(struct snd_usb_substream *subs)
45 {
46 	struct audioformat *fp, *n;
47 
48 	if (!subs->num_formats)
49 		return; /* not initialized */
50 	list_for_each_entry_safe(fp, n, &subs->fmt_list, list) {
51 		kfree(fp->rate_table);
52 		kfree(fp->chmap);
53 		kfree(fp);
54 	}
55 	kfree(subs->rate_list.list);
56 }
57 
58 
59 /*
60  * free a usb stream instance
61  */
62 static void snd_usb_audio_stream_free(struct snd_usb_stream *stream)
63 {
64 	free_substream(&stream->substream[0]);
65 	free_substream(&stream->substream[1]);
66 	list_del(&stream->list);
67 	kfree(stream);
68 }
69 
70 static void snd_usb_audio_pcm_free(struct snd_pcm *pcm)
71 {
72 	struct snd_usb_stream *stream = pcm->private_data;
73 	if (stream) {
74 		stream->pcm = NULL;
75 		snd_usb_audio_stream_free(stream);
76 	}
77 }
78 
79 /*
80  * initialize the substream instance.
81  */
82 
83 static void snd_usb_init_substream(struct snd_usb_stream *as,
84 				   int stream,
85 				   struct audioformat *fp)
86 {
87 	struct snd_usb_substream *subs = &as->substream[stream];
88 
89 	INIT_LIST_HEAD(&subs->fmt_list);
90 	spin_lock_init(&subs->lock);
91 
92 	subs->stream = as;
93 	subs->direction = stream;
94 	subs->dev = as->chip->dev;
95 	subs->txfr_quirk = as->chip->txfr_quirk;
96 	subs->tx_length_quirk = as->chip->tx_length_quirk;
97 	subs->speed = snd_usb_get_speed(subs->dev);
98 	subs->pkt_offset_adj = 0;
99 
100 	snd_usb_set_pcm_ops(as->pcm, stream);
101 
102 	list_add_tail(&fp->list, &subs->fmt_list);
103 	subs->formats |= fp->formats;
104 	subs->num_formats++;
105 	subs->fmt_type = fp->fmt_type;
106 	subs->ep_num = fp->endpoint;
107 	if (fp->channels > subs->channels_max)
108 		subs->channels_max = fp->channels;
109 
110 	snd_usb_preallocate_buffer(subs);
111 }
112 
113 /* kctl callbacks for usb-audio channel maps */
114 static int usb_chmap_ctl_info(struct snd_kcontrol *kcontrol,
115 			      struct snd_ctl_elem_info *uinfo)
116 {
117 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
118 	struct snd_usb_substream *subs = info->private_data;
119 
120 	uinfo->type = SNDRV_CTL_ELEM_TYPE_INTEGER;
121 	uinfo->count = subs->channels_max;
122 	uinfo->value.integer.min = 0;
123 	uinfo->value.integer.max = SNDRV_CHMAP_LAST;
124 	return 0;
125 }
126 
127 /* check whether a duplicated entry exists in the audiofmt list */
128 static bool have_dup_chmap(struct snd_usb_substream *subs,
129 			   struct audioformat *fp)
130 {
131 	struct audioformat *prev = fp;
132 
133 	list_for_each_entry_continue_reverse(prev, &subs->fmt_list, list) {
134 		if (prev->chmap &&
135 		    !memcmp(prev->chmap, fp->chmap, sizeof(*fp->chmap)))
136 			return true;
137 	}
138 	return false;
139 }
140 
141 static int usb_chmap_ctl_tlv(struct snd_kcontrol *kcontrol, int op_flag,
142 			     unsigned int size, unsigned int __user *tlv)
143 {
144 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
145 	struct snd_usb_substream *subs = info->private_data;
146 	struct audioformat *fp;
147 	unsigned int __user *dst;
148 	int count = 0;
149 
150 	if (size < 8)
151 		return -ENOMEM;
152 	if (put_user(SNDRV_CTL_TLVT_CONTAINER, tlv))
153 		return -EFAULT;
154 	size -= 8;
155 	dst = tlv + 2;
156 	list_for_each_entry(fp, &subs->fmt_list, list) {
157 		int i, ch_bytes;
158 
159 		if (!fp->chmap)
160 			continue;
161 		if (have_dup_chmap(subs, fp))
162 			continue;
163 		/* copy the entry */
164 		ch_bytes = fp->chmap->channels * 4;
165 		if (size < 8 + ch_bytes)
166 			return -ENOMEM;
167 		if (put_user(SNDRV_CTL_TLVT_CHMAP_FIXED, dst) ||
168 		    put_user(ch_bytes, dst + 1))
169 			return -EFAULT;
170 		dst += 2;
171 		for (i = 0; i < fp->chmap->channels; i++, dst++) {
172 			if (put_user(fp->chmap->map[i], dst))
173 				return -EFAULT;
174 		}
175 
176 		count += 8 + ch_bytes;
177 		size -= 8 + ch_bytes;
178 	}
179 	if (put_user(count, tlv + 1))
180 		return -EFAULT;
181 	return 0;
182 }
183 
184 static int usb_chmap_ctl_get(struct snd_kcontrol *kcontrol,
185 			     struct snd_ctl_elem_value *ucontrol)
186 {
187 	struct snd_pcm_chmap *info = snd_kcontrol_chip(kcontrol);
188 	struct snd_usb_substream *subs = info->private_data;
189 	struct snd_pcm_chmap_elem *chmap = NULL;
190 	int i;
191 
192 	memset(ucontrol->value.integer.value, 0,
193 	       sizeof(ucontrol->value.integer.value));
194 	if (subs->cur_audiofmt)
195 		chmap = subs->cur_audiofmt->chmap;
196 	if (chmap) {
197 		for (i = 0; i < chmap->channels; i++)
198 			ucontrol->value.integer.value[i] = chmap->map[i];
199 	}
200 	return 0;
201 }
202 
203 /* create a chmap kctl assigned to the given USB substream */
204 static int add_chmap(struct snd_pcm *pcm, int stream,
205 		     struct snd_usb_substream *subs)
206 {
207 	struct audioformat *fp;
208 	struct snd_pcm_chmap *chmap;
209 	struct snd_kcontrol *kctl;
210 	int err;
211 
212 	list_for_each_entry(fp, &subs->fmt_list, list)
213 		if (fp->chmap)
214 			goto ok;
215 	/* no chmap is found */
216 	return 0;
217 
218  ok:
219 	err = snd_pcm_add_chmap_ctls(pcm, stream, NULL, 0, 0, &chmap);
220 	if (err < 0)
221 		return err;
222 
223 	/* override handlers */
224 	chmap->private_data = subs;
225 	kctl = chmap->kctl;
226 	kctl->info = usb_chmap_ctl_info;
227 	kctl->get = usb_chmap_ctl_get;
228 	kctl->tlv.c = usb_chmap_ctl_tlv;
229 
230 	return 0;
231 }
232 
233 /* convert from USB ChannelConfig bits to ALSA chmap element */
234 static struct snd_pcm_chmap_elem *convert_chmap(int channels, unsigned int bits,
235 						int protocol)
236 {
237 	static unsigned int uac1_maps[] = {
238 		SNDRV_CHMAP_FL,		/* left front */
239 		SNDRV_CHMAP_FR,		/* right front */
240 		SNDRV_CHMAP_FC,		/* center front */
241 		SNDRV_CHMAP_LFE,	/* LFE */
242 		SNDRV_CHMAP_SL,		/* left surround */
243 		SNDRV_CHMAP_SR,		/* right surround */
244 		SNDRV_CHMAP_FLC,	/* left of center */
245 		SNDRV_CHMAP_FRC,	/* right of center */
246 		SNDRV_CHMAP_RC,		/* surround */
247 		SNDRV_CHMAP_SL,		/* side left */
248 		SNDRV_CHMAP_SR,		/* side right */
249 		SNDRV_CHMAP_TC,		/* top */
250 		0 /* terminator */
251 	};
252 	static unsigned int uac2_maps[] = {
253 		SNDRV_CHMAP_FL,		/* front left */
254 		SNDRV_CHMAP_FR,		/* front right */
255 		SNDRV_CHMAP_FC,		/* front center */
256 		SNDRV_CHMAP_LFE,	/* LFE */
257 		SNDRV_CHMAP_RL,		/* back left */
258 		SNDRV_CHMAP_RR,		/* back right */
259 		SNDRV_CHMAP_FLC,	/* front left of center */
260 		SNDRV_CHMAP_FRC,	/* front right of center */
261 		SNDRV_CHMAP_RC,		/* back center */
262 		SNDRV_CHMAP_SL,		/* side left */
263 		SNDRV_CHMAP_SR,		/* side right */
264 		SNDRV_CHMAP_TC,		/* top center */
265 		SNDRV_CHMAP_TFL,	/* top front left */
266 		SNDRV_CHMAP_TFC,	/* top front center */
267 		SNDRV_CHMAP_TFR,	/* top front right */
268 		SNDRV_CHMAP_TRL,	/* top back left */
269 		SNDRV_CHMAP_TRC,	/* top back center */
270 		SNDRV_CHMAP_TRR,	/* top back right */
271 		SNDRV_CHMAP_TFLC,	/* top front left of center */
272 		SNDRV_CHMAP_TFRC,	/* top front right of center */
273 		SNDRV_CHMAP_LLFE,	/* left LFE */
274 		SNDRV_CHMAP_RLFE,	/* right LFE */
275 		SNDRV_CHMAP_TSL,	/* top side left */
276 		SNDRV_CHMAP_TSR,	/* top side right */
277 		SNDRV_CHMAP_BC,		/* bottom center */
278 		SNDRV_CHMAP_RLC,	/* back left of center */
279 		SNDRV_CHMAP_RRC,	/* back right of center */
280 		0 /* terminator */
281 	};
282 	struct snd_pcm_chmap_elem *chmap;
283 	const unsigned int *maps;
284 	int c;
285 
286 	if (channels > ARRAY_SIZE(chmap->map))
287 		return NULL;
288 
289 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
290 	if (!chmap)
291 		return NULL;
292 
293 	maps = protocol == UAC_VERSION_2 ? uac2_maps : uac1_maps;
294 	chmap->channels = channels;
295 	c = 0;
296 
297 	if (bits) {
298 		for (; bits && *maps; maps++, bits >>= 1)
299 			if (bits & 1)
300 				chmap->map[c++] = *maps;
301 	} else {
302 		/* If we're missing wChannelConfig, then guess something
303 		    to make sure the channel map is not skipped entirely */
304 		if (channels == 1)
305 			chmap->map[c++] = SNDRV_CHMAP_MONO;
306 		else
307 			for (; c < channels && *maps; maps++)
308 				chmap->map[c++] = *maps;
309 	}
310 
311 	for (; c < channels; c++)
312 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
313 
314 	return chmap;
315 }
316 
317 /* UAC3 device stores channels information in Cluster Descriptors */
318 static struct
319 snd_pcm_chmap_elem *convert_chmap_v3(struct uac3_cluster_header_descriptor
320 								*cluster)
321 {
322 	unsigned int channels = cluster->bNrChannels;
323 	struct snd_pcm_chmap_elem *chmap;
324 	void *p = cluster;
325 	int len, c;
326 
327 	if (channels > ARRAY_SIZE(chmap->map))
328 		return NULL;
329 
330 	chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
331 	if (!chmap)
332 		return NULL;
333 
334 	len = le16_to_cpu(cluster->wLength);
335 	c = 0;
336 	p += sizeof(struct uac3_cluster_header_descriptor);
337 
338 	while (((p - (void *)cluster) < len) && (c < channels)) {
339 		struct uac3_cluster_segment_descriptor *cs_desc = p;
340 		u16 cs_len;
341 		u8 cs_type;
342 
343 		cs_len = le16_to_cpu(cs_desc->wLength);
344 		cs_type = cs_desc->bSegmentType;
345 
346 		if (cs_type == UAC3_CHANNEL_INFORMATION) {
347 			struct uac3_cluster_information_segment_descriptor *is = p;
348 			unsigned char map;
349 
350 			/*
351 			 * TODO: this conversion is not complete, update it
352 			 * after adding UAC3 values to asound.h
353 			 */
354 			switch (is->bChRelationship) {
355 			case UAC3_CH_MONO:
356 				map = SNDRV_CHMAP_MONO;
357 				break;
358 			case UAC3_CH_LEFT:
359 			case UAC3_CH_FRONT_LEFT:
360 			case UAC3_CH_HEADPHONE_LEFT:
361 				map = SNDRV_CHMAP_FL;
362 				break;
363 			case UAC3_CH_RIGHT:
364 			case UAC3_CH_FRONT_RIGHT:
365 			case UAC3_CH_HEADPHONE_RIGHT:
366 				map = SNDRV_CHMAP_FR;
367 				break;
368 			case UAC3_CH_FRONT_CENTER:
369 				map = SNDRV_CHMAP_FC;
370 				break;
371 			case UAC3_CH_FRONT_LEFT_OF_CENTER:
372 				map = SNDRV_CHMAP_FLC;
373 				break;
374 			case UAC3_CH_FRONT_RIGHT_OF_CENTER:
375 				map = SNDRV_CHMAP_FRC;
376 				break;
377 			case UAC3_CH_SIDE_LEFT:
378 				map = SNDRV_CHMAP_SL;
379 				break;
380 			case UAC3_CH_SIDE_RIGHT:
381 				map = SNDRV_CHMAP_SR;
382 				break;
383 			case UAC3_CH_BACK_LEFT:
384 				map = SNDRV_CHMAP_RL;
385 				break;
386 			case UAC3_CH_BACK_RIGHT:
387 				map = SNDRV_CHMAP_RR;
388 				break;
389 			case UAC3_CH_BACK_CENTER:
390 				map = SNDRV_CHMAP_RC;
391 				break;
392 			case UAC3_CH_BACK_LEFT_OF_CENTER:
393 				map = SNDRV_CHMAP_RLC;
394 				break;
395 			case UAC3_CH_BACK_RIGHT_OF_CENTER:
396 				map = SNDRV_CHMAP_RRC;
397 				break;
398 			case UAC3_CH_TOP_CENTER:
399 				map = SNDRV_CHMAP_TC;
400 				break;
401 			case UAC3_CH_TOP_FRONT_LEFT:
402 				map = SNDRV_CHMAP_TFL;
403 				break;
404 			case UAC3_CH_TOP_FRONT_RIGHT:
405 				map = SNDRV_CHMAP_TFR;
406 				break;
407 			case UAC3_CH_TOP_FRONT_CENTER:
408 				map = SNDRV_CHMAP_TFC;
409 				break;
410 			case UAC3_CH_TOP_FRONT_LOC:
411 				map = SNDRV_CHMAP_TFLC;
412 				break;
413 			case UAC3_CH_TOP_FRONT_ROC:
414 				map = SNDRV_CHMAP_TFRC;
415 				break;
416 			case UAC3_CH_TOP_SIDE_LEFT:
417 				map = SNDRV_CHMAP_TSL;
418 				break;
419 			case UAC3_CH_TOP_SIDE_RIGHT:
420 				map = SNDRV_CHMAP_TSR;
421 				break;
422 			case UAC3_CH_TOP_BACK_LEFT:
423 				map = SNDRV_CHMAP_TRL;
424 				break;
425 			case UAC3_CH_TOP_BACK_RIGHT:
426 				map = SNDRV_CHMAP_TRR;
427 				break;
428 			case UAC3_CH_TOP_BACK_CENTER:
429 				map = SNDRV_CHMAP_TRC;
430 				break;
431 			case UAC3_CH_BOTTOM_CENTER:
432 				map = SNDRV_CHMAP_BC;
433 				break;
434 			case UAC3_CH_LOW_FREQUENCY_EFFECTS:
435 				map = SNDRV_CHMAP_LFE;
436 				break;
437 			case UAC3_CH_LFE_LEFT:
438 				map = SNDRV_CHMAP_LLFE;
439 				break;
440 			case UAC3_CH_LFE_RIGHT:
441 				map = SNDRV_CHMAP_RLFE;
442 				break;
443 			case UAC3_CH_RELATIONSHIP_UNDEFINED:
444 			default:
445 				map = SNDRV_CHMAP_UNKNOWN;
446 				break;
447 			}
448 			chmap->map[c++] = map;
449 		}
450 		p += cs_len;
451 	}
452 
453 	if (channels < c)
454 		pr_err("%s: channel number mismatch\n", __func__);
455 
456 	chmap->channels = channels;
457 
458 	for (; c < channels; c++)
459 		chmap->map[c] = SNDRV_CHMAP_UNKNOWN;
460 
461 	return chmap;
462 }
463 
464 /*
465  * add this endpoint to the chip instance.
466  * if a stream with the same endpoint already exists, append to it.
467  * if not, create a new pcm stream. note, fp is added to the substream
468  * fmt_list and will be freed on the chip instance release. do not free
469  * fp or do remove it from the substream fmt_list to avoid double-free.
470  */
471 int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
472 			     int stream,
473 			     struct audioformat *fp)
474 {
475 	struct snd_usb_stream *as;
476 	struct snd_usb_substream *subs;
477 	struct snd_pcm *pcm;
478 	int err;
479 
480 	list_for_each_entry(as, &chip->pcm_list, list) {
481 		if (as->fmt_type != fp->fmt_type)
482 			continue;
483 		subs = &as->substream[stream];
484 		if (subs->ep_num == fp->endpoint) {
485 			list_add_tail(&fp->list, &subs->fmt_list);
486 			subs->num_formats++;
487 			subs->formats |= fp->formats;
488 			return 0;
489 		}
490 	}
491 	/* look for an empty stream */
492 	list_for_each_entry(as, &chip->pcm_list, list) {
493 		if (as->fmt_type != fp->fmt_type)
494 			continue;
495 		subs = &as->substream[stream];
496 		if (subs->ep_num)
497 			continue;
498 		err = snd_pcm_new_stream(as->pcm, stream, 1);
499 		if (err < 0)
500 			return err;
501 		snd_usb_init_substream(as, stream, fp);
502 		return add_chmap(as->pcm, stream, subs);
503 	}
504 
505 	/* create a new pcm */
506 	as = kzalloc(sizeof(*as), GFP_KERNEL);
507 	if (!as)
508 		return -ENOMEM;
509 	as->pcm_index = chip->pcm_devs;
510 	as->chip = chip;
511 	as->fmt_type = fp->fmt_type;
512 	err = snd_pcm_new(chip->card, "USB Audio", chip->pcm_devs,
513 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 1 : 0,
514 			  stream == SNDRV_PCM_STREAM_PLAYBACK ? 0 : 1,
515 			  &pcm);
516 	if (err < 0) {
517 		kfree(as);
518 		return err;
519 	}
520 	as->pcm = pcm;
521 	pcm->private_data = as;
522 	pcm->private_free = snd_usb_audio_pcm_free;
523 	pcm->info_flags = 0;
524 	if (chip->pcm_devs > 0)
525 		sprintf(pcm->name, "USB Audio #%d", chip->pcm_devs);
526 	else
527 		strcpy(pcm->name, "USB Audio");
528 
529 	snd_usb_init_substream(as, stream, fp);
530 
531 	/*
532 	 * Keep using head insertion for M-Audio Audiophile USB (tm) which has a
533 	 * fix to swap capture stream order in conf/cards/USB-audio.conf
534 	 */
535 	if (chip->usb_id == USB_ID(0x0763, 0x2003))
536 		list_add(&as->list, &chip->pcm_list);
537 	else
538 		list_add_tail(&as->list, &chip->pcm_list);
539 
540 	chip->pcm_devs++;
541 
542 	snd_usb_proc_pcm_format_add(as);
543 
544 	return add_chmap(pcm, stream, &as->substream[stream]);
545 }
546 
547 static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
548 					 struct usb_host_interface *alts,
549 					 int protocol, int iface_no)
550 {
551 	/* parsed with a v1 header here. that's ok as we only look at the
552 	 * header first which is the same for both versions */
553 	struct uac_iso_endpoint_descriptor *csep;
554 	struct usb_interface_descriptor *altsd = get_iface_desc(alts);
555 	int attributes = 0;
556 
557 	csep = snd_usb_find_desc(alts->endpoint[0].extra, alts->endpoint[0].extralen, NULL, USB_DT_CS_ENDPOINT);
558 
559 	/* Creamware Noah has this descriptor after the 2nd endpoint */
560 	if (!csep && altsd->bNumEndpoints >= 2)
561 		csep = snd_usb_find_desc(alts->endpoint[1].extra, alts->endpoint[1].extralen, NULL, USB_DT_CS_ENDPOINT);
562 
563 	/*
564 	 * If we can't locate the USB_DT_CS_ENDPOINT descriptor in the extra
565 	 * bytes after the first endpoint, go search the entire interface.
566 	 * Some devices have it directly *before* the standard endpoint.
567 	 */
568 	if (!csep)
569 		csep = snd_usb_find_desc(alts->extra, alts->extralen, NULL, USB_DT_CS_ENDPOINT);
570 
571 	if (!csep || csep->bLength < 7 ||
572 	    csep->bDescriptorSubtype != UAC_EP_GENERAL) {
573 		usb_audio_warn(chip,
574 			       "%u:%d : no or invalid class specific endpoint descriptor\n",
575 			       iface_no, altsd->bAlternateSetting);
576 		return 0;
577 	}
578 
579 	if (protocol == UAC_VERSION_1) {
580 		attributes = csep->bmAttributes;
581 	} else if (protocol == UAC_VERSION_2) {
582 		struct uac2_iso_endpoint_descriptor *csep2 =
583 			(struct uac2_iso_endpoint_descriptor *) csep;
584 
585 		attributes = csep->bmAttributes & UAC_EP_CS_ATTR_FILL_MAX;
586 
587 		/* emulate the endpoint attributes of a v1 device */
588 		if (csep2->bmControls & UAC2_CONTROL_PITCH)
589 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
590 	} else { /* UAC_VERSION_3 */
591 		struct uac3_iso_endpoint_descriptor *csep3 =
592 			(struct uac3_iso_endpoint_descriptor *) csep;
593 
594 		/* emulate the endpoint attributes of a v1 device */
595 		if (le32_to_cpu(csep3->bmControls) & UAC2_CONTROL_PITCH)
596 			attributes |= UAC_EP_CS_ATTR_PITCH_CONTROL;
597 	}
598 
599 	return attributes;
600 }
601 
602 /* find an input terminal descriptor (either UAC1 or UAC2) with the given
603  * terminal id
604  */
605 static void *
606 snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
607 					       int terminal_id)
608 {
609 	struct uac2_input_terminal_descriptor *term = NULL;
610 
611 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
612 					       ctrl_iface->extralen,
613 					       term, UAC_INPUT_TERMINAL))) {
614 		if (term->bTerminalID == terminal_id)
615 			return term;
616 	}
617 
618 	return NULL;
619 }
620 
621 static void *
622 snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
623 					int terminal_id)
624 {
625 	/* OK to use with both UAC2 and UAC3 */
626 	struct uac2_output_terminal_descriptor *term = NULL;
627 
628 	while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
629 					       ctrl_iface->extralen,
630 					       term, UAC_OUTPUT_TERMINAL))) {
631 		if (term->bTerminalID == terminal_id)
632 			return term;
633 	}
634 
635 	return NULL;
636 }
637 
638 static struct audioformat *
639 audio_format_alloc_init(struct snd_usb_audio *chip,
640 		       struct usb_host_interface *alts,
641 		       int protocol, int iface_no, int altset_idx,
642 		       int altno, int num_channels, int clock)
643 {
644 	struct audioformat *fp;
645 
646 	fp = kzalloc(sizeof(*fp), GFP_KERNEL);
647 	if (!fp)
648 		return NULL;
649 
650 	fp->iface = iface_no;
651 	fp->altsetting = altno;
652 	fp->altset_idx = altset_idx;
653 	fp->endpoint = get_endpoint(alts, 0)->bEndpointAddress;
654 	fp->ep_attr = get_endpoint(alts, 0)->bmAttributes;
655 	fp->datainterval = snd_usb_parse_datainterval(chip, alts);
656 	fp->protocol = protocol;
657 	fp->maxpacksize = le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
658 	fp->channels = num_channels;
659 	if (snd_usb_get_speed(chip->dev) == USB_SPEED_HIGH)
660 		fp->maxpacksize = (((fp->maxpacksize >> 11) & 3) + 1)
661 				* (fp->maxpacksize & 0x7ff);
662 	fp->clock = clock;
663 	INIT_LIST_HEAD(&fp->list);
664 
665 	return fp;
666 }
667 
668 static struct audioformat *
669 snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
670 			      struct usb_host_interface *alts,
671 			      int protocol, int iface_no, int altset_idx,
672 			      int altno, int stream, int bm_quirk)
673 {
674 	struct usb_device *dev = chip->dev;
675 	struct uac_format_type_i_continuous_descriptor *fmt;
676 	unsigned int num_channels = 0, chconfig = 0;
677 	struct audioformat *fp;
678 	int clock = 0;
679 	u64 format;
680 
681 	/* get audio formats */
682 	if (protocol == UAC_VERSION_1) {
683 		struct uac1_as_header_descriptor *as =
684 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
685 						NULL, UAC_AS_GENERAL);
686 		struct uac_input_terminal_descriptor *iterm;
687 
688 		if (!as) {
689 			dev_err(&dev->dev,
690 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
691 				iface_no, altno);
692 			return NULL;
693 		}
694 
695 		if (as->bLength < sizeof(*as)) {
696 			dev_err(&dev->dev,
697 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
698 				iface_no, altno);
699 			return NULL;
700 		}
701 
702 		format = le16_to_cpu(as->wFormatTag); /* remember the format value */
703 
704 		iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
705 							     as->bTerminalLink);
706 		if (iterm) {
707 			num_channels = iterm->bNrChannels;
708 			chconfig = le16_to_cpu(iterm->wChannelConfig);
709 		}
710 	} else { /* UAC_VERSION_2 */
711 		struct uac2_input_terminal_descriptor *input_term;
712 		struct uac2_output_terminal_descriptor *output_term;
713 		struct uac2_as_header_descriptor *as =
714 			snd_usb_find_csint_desc(alts->extra, alts->extralen,
715 						NULL, UAC_AS_GENERAL);
716 
717 		if (!as) {
718 			dev_err(&dev->dev,
719 				"%u:%d : UAC_AS_GENERAL descriptor not found\n",
720 				iface_no, altno);
721 			return NULL;
722 		}
723 
724 		if (as->bLength < sizeof(*as)) {
725 			dev_err(&dev->dev,
726 				"%u:%d : invalid UAC_AS_GENERAL desc\n",
727 				iface_no, altno);
728 			return NULL;
729 		}
730 
731 		num_channels = as->bNrChannels;
732 		format = le32_to_cpu(as->bmFormats);
733 		chconfig = le32_to_cpu(as->bmChannelConfig);
734 
735 		/*
736 		 * lookup the terminal associated to this interface
737 		 * to extract the clock
738 		 */
739 		input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
740 								    as->bTerminalLink);
741 		if (input_term) {
742 			clock = input_term->bCSourceID;
743 			if (!chconfig && (num_channels == input_term->bNrChannels))
744 				chconfig = le32_to_cpu(input_term->bmChannelConfig);
745 			goto found_clock;
746 		}
747 
748 		output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
749 								      as->bTerminalLink);
750 		if (output_term) {
751 			clock = output_term->bCSourceID;
752 			goto found_clock;
753 		}
754 
755 		dev_err(&dev->dev,
756 			"%u:%d : bogus bTerminalLink %d\n",
757 			iface_no, altno, as->bTerminalLink);
758 		return NULL;
759 	}
760 
761 found_clock:
762 	/* get format type */
763 	fmt = snd_usb_find_csint_desc(alts->extra, alts->extralen,
764 				      NULL, UAC_FORMAT_TYPE);
765 	if (!fmt) {
766 		dev_err(&dev->dev,
767 			"%u:%d : no UAC_FORMAT_TYPE desc\n",
768 			iface_no, altno);
769 		return NULL;
770 	}
771 	if (((protocol == UAC_VERSION_1) && (fmt->bLength < 8))
772 			|| ((protocol == UAC_VERSION_2) &&
773 					(fmt->bLength < 6))) {
774 		dev_err(&dev->dev,
775 			"%u:%d : invalid UAC_FORMAT_TYPE desc\n",
776 			iface_no, altno);
777 		return NULL;
778 	}
779 
780 	/*
781 	 * Blue Microphones workaround: The last altsetting is
782 	 * identical with the previous one, except for a larger
783 	 * packet size, but is actually a mislabeled two-channel
784 	 * setting; ignore it.
785 	 *
786 	 * Part 2: analyze quirk flag and format
787 	 */
788 	if (bm_quirk && fmt->bNrChannels == 1 && fmt->bSubframeSize == 2)
789 		return NULL;
790 
791 	fp = audio_format_alloc_init(chip, alts, protocol, iface_no,
792 				     altset_idx, altno, num_channels, clock);
793 	if (!fp)
794 		return ERR_PTR(-ENOMEM);
795 
796 	fp->attributes = parse_uac_endpoint_attributes(chip, alts, protocol,
797 						       iface_no);
798 
799 	/* some quirks for attributes here */
800 	snd_usb_audioformat_attributes_quirk(chip, fp, stream);
801 
802 	/* ok, let's parse further... */
803 	if (snd_usb_parse_audio_format(chip, fp, format,
804 					fmt, stream) < 0) {
805 		kfree(fp->rate_table);
806 		kfree(fp);
807 		return NULL;
808 	}
809 
810 	/* Create chmap */
811 	if (fp->channels != num_channels)
812 		chconfig = 0;
813 
814 	fp->chmap = convert_chmap(fp->channels, chconfig, protocol);
815 
816 	return fp;
817 }
818 
819 static struct audioformat *
820 snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
821 			     struct usb_host_interface *alts,
822 			     int iface_no, int altset_idx,
823 			     int altno, int stream)
824 {
825 	struct usb_device *dev = chip->dev;
826 	struct uac3_input_terminal_descriptor *input_term;
827 	struct uac3_output_terminal_descriptor *output_term;
828 	struct uac3_cluster_header_descriptor *cluster;
829 	struct uac3_as_header_descriptor *as = NULL;
830 	struct uac3_hc_descriptor_header hc_header;
831 	struct snd_pcm_chmap_elem *chmap;
832 	unsigned char badd_profile;
833 	u64 badd_formats = 0;
834 	unsigned int num_channels;
835 	struct audioformat *fp;
836 	u16 cluster_id, wLength;
837 	int clock = 0;
838 	int err;
839 
840 	badd_profile = chip->badd_profile;
841 
842 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
843 		unsigned int maxpacksize =
844 			le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize);
845 
846 		switch (maxpacksize) {
847 		default:
848 			dev_err(&dev->dev,
849 				"%u:%d : incorrect wMaxPacketSize for BADD profile\n",
850 				iface_no, altno);
851 			return NULL;
852 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_16:
853 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_16:
854 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
855 			num_channels = 1;
856 			break;
857 		case UAC3_BADD_EP_MAXPSIZE_SYNC_MONO_24:
858 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_MONO_24:
859 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
860 			num_channels = 1;
861 			break;
862 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_16:
863 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_16:
864 			badd_formats = SNDRV_PCM_FMTBIT_S16_LE;
865 			num_channels = 2;
866 			break;
867 		case UAC3_BADD_EP_MAXPSIZE_SYNC_STEREO_24:
868 		case UAC3_BADD_EP_MAXPSIZE_ASYNC_STEREO_24:
869 			badd_formats = SNDRV_PCM_FMTBIT_S24_3LE;
870 			num_channels = 2;
871 			break;
872 		}
873 
874 		chmap = kzalloc(sizeof(*chmap), GFP_KERNEL);
875 		if (!chmap)
876 			return ERR_PTR(-ENOMEM);
877 
878 		if (num_channels == 1) {
879 			chmap->map[0] = SNDRV_CHMAP_MONO;
880 		} else {
881 			chmap->map[0] = SNDRV_CHMAP_FL;
882 			chmap->map[1] = SNDRV_CHMAP_FR;
883 		}
884 
885 		chmap->channels = num_channels;
886 		clock = UAC3_BADD_CS_ID9;
887 		goto found_clock;
888 	}
889 
890 	as = snd_usb_find_csint_desc(alts->extra, alts->extralen,
891 				     NULL, UAC_AS_GENERAL);
892 	if (!as) {
893 		dev_err(&dev->dev,
894 			"%u:%d : UAC_AS_GENERAL descriptor not found\n",
895 			iface_no, altno);
896 		return NULL;
897 	}
898 
899 	if (as->bLength < sizeof(*as)) {
900 		dev_err(&dev->dev,
901 			"%u:%d : invalid UAC_AS_GENERAL desc\n",
902 			iface_no, altno);
903 		return NULL;
904 	}
905 
906 	cluster_id = le16_to_cpu(as->wClusterDescrID);
907 	if (!cluster_id) {
908 		dev_err(&dev->dev,
909 			"%u:%d : no cluster descriptor\n",
910 			iface_no, altno);
911 		return NULL;
912 	}
913 
914 	/*
915 	 * Get number of channels and channel map through
916 	 * High Capability Cluster Descriptor
917 	 *
918 	 * First step: get High Capability header and
919 	 * read size of Cluster Descriptor
920 	 */
921 	err = snd_usb_ctl_msg(chip->dev,
922 			usb_rcvctrlpipe(chip->dev, 0),
923 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
924 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
925 			cluster_id,
926 			snd_usb_ctrl_intf(chip),
927 			&hc_header, sizeof(hc_header));
928 	if (err < 0)
929 		return ERR_PTR(err);
930 	else if (err != sizeof(hc_header)) {
931 		dev_err(&dev->dev,
932 			"%u:%d : can't get High Capability descriptor\n",
933 			iface_no, altno);
934 		return ERR_PTR(-EIO);
935 	}
936 
937 	/*
938 	 * Second step: allocate needed amount of memory
939 	 * and request Cluster Descriptor
940 	 */
941 	wLength = le16_to_cpu(hc_header.wLength);
942 	cluster = kzalloc(wLength, GFP_KERNEL);
943 	if (!cluster)
944 		return ERR_PTR(-ENOMEM);
945 	err = snd_usb_ctl_msg(chip->dev,
946 			usb_rcvctrlpipe(chip->dev, 0),
947 			UAC3_CS_REQ_HIGH_CAPABILITY_DESCRIPTOR,
948 			USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
949 			cluster_id,
950 			snd_usb_ctrl_intf(chip),
951 			cluster, wLength);
952 	if (err < 0) {
953 		kfree(cluster);
954 		return ERR_PTR(err);
955 	} else if (err != wLength) {
956 		dev_err(&dev->dev,
957 			"%u:%d : can't get Cluster Descriptor\n",
958 			iface_no, altno);
959 		kfree(cluster);
960 		return ERR_PTR(-EIO);
961 	}
962 
963 	num_channels = cluster->bNrChannels;
964 	chmap = convert_chmap_v3(cluster);
965 	kfree(cluster);
966 
967 	/*
968 	 * lookup the terminal associated to this interface
969 	 * to extract the clock
970 	 */
971 	input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
972 							    as->bTerminalLink);
973 	if (input_term) {
974 		clock = input_term->bCSourceID;
975 		goto found_clock;
976 	}
977 
978 	output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
979 							     as->bTerminalLink);
980 	if (output_term) {
981 		clock = output_term->bCSourceID;
982 		goto found_clock;
983 	}
984 
985 	dev_err(&dev->dev, "%u:%d : bogus bTerminalLink %d\n",
986 			iface_no, altno, as->bTerminalLink);
987 	kfree(chmap);
988 	return NULL;
989 
990 found_clock:
991 	fp = audio_format_alloc_init(chip, alts, UAC_VERSION_3, iface_no,
992 				     altset_idx, altno, num_channels, clock);
993 	if (!fp) {
994 		kfree(chmap);
995 		return ERR_PTR(-ENOMEM);
996 	}
997 
998 	fp->chmap = chmap;
999 
1000 	if (badd_profile >= UAC3_FUNCTION_SUBCLASS_GENERIC_IO) {
1001 		fp->attributes = 0; /* No attributes */
1002 
1003 		fp->fmt_type = UAC_FORMAT_TYPE_I;
1004 		fp->formats = badd_formats;
1005 
1006 		fp->nr_rates = 0;	/* SNDRV_PCM_RATE_CONTINUOUS */
1007 		fp->rate_min = UAC3_BADD_SAMPLING_RATE;
1008 		fp->rate_max = UAC3_BADD_SAMPLING_RATE;
1009 		fp->rates = SNDRV_PCM_RATE_CONTINUOUS;
1010 
1011 	} else {
1012 		fp->attributes = parse_uac_endpoint_attributes(chip, alts,
1013 							       UAC_VERSION_3,
1014 							       iface_no);
1015 		/* ok, let's parse further... */
1016 		if (snd_usb_parse_audio_format_v3(chip, fp, as, stream) < 0) {
1017 			kfree(fp->chmap);
1018 			kfree(fp->rate_table);
1019 			kfree(fp);
1020 			return NULL;
1021 		}
1022 	}
1023 
1024 	return fp;
1025 }
1026 
1027 int snd_usb_parse_audio_interface(struct snd_usb_audio *chip, int iface_no)
1028 {
1029 	struct usb_device *dev;
1030 	struct usb_interface *iface;
1031 	struct usb_host_interface *alts;
1032 	struct usb_interface_descriptor *altsd;
1033 	int i, altno, err, stream;
1034 	struct audioformat *fp = NULL;
1035 	int num, protocol;
1036 
1037 	dev = chip->dev;
1038 
1039 	/* parse the interface's altsettings */
1040 	iface = usb_ifnum_to_if(dev, iface_no);
1041 
1042 	num = iface->num_altsetting;
1043 
1044 	/*
1045 	 * Dallas DS4201 workaround: It presents 5 altsettings, but the last
1046 	 * one misses syncpipe, and does not produce any sound.
1047 	 */
1048 	if (chip->usb_id == USB_ID(0x04fa, 0x4201))
1049 		num = 4;
1050 
1051 	for (i = 0; i < num; i++) {
1052 		alts = &iface->altsetting[i];
1053 		altsd = get_iface_desc(alts);
1054 		protocol = altsd->bInterfaceProtocol;
1055 		/* skip invalid one */
1056 		if (((altsd->bInterfaceClass != USB_CLASS_AUDIO ||
1057 		      (altsd->bInterfaceSubClass != USB_SUBCLASS_AUDIOSTREAMING &&
1058 		       altsd->bInterfaceSubClass != USB_SUBCLASS_VENDOR_SPEC)) &&
1059 		     altsd->bInterfaceClass != USB_CLASS_VENDOR_SPEC) ||
1060 		    altsd->bNumEndpoints < 1 ||
1061 		    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) == 0)
1062 			continue;
1063 		/* must be isochronous */
1064 		if ((get_endpoint(alts, 0)->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) !=
1065 		    USB_ENDPOINT_XFER_ISOC)
1066 			continue;
1067 		/* check direction */
1068 		stream = (get_endpoint(alts, 0)->bEndpointAddress & USB_DIR_IN) ?
1069 			SNDRV_PCM_STREAM_CAPTURE : SNDRV_PCM_STREAM_PLAYBACK;
1070 		altno = altsd->bAlternateSetting;
1071 
1072 		if (snd_usb_apply_interface_quirk(chip, iface_no, altno))
1073 			continue;
1074 
1075 		/*
1076 		 * Roland audio streaming interfaces are marked with protocols
1077 		 * 0/1/2, but are UAC 1 compatible.
1078 		 */
1079 		if (USB_ID_VENDOR(chip->usb_id) == 0x0582 &&
1080 		    altsd->bInterfaceClass == USB_CLASS_VENDOR_SPEC &&
1081 		    protocol <= 2)
1082 			protocol = UAC_VERSION_1;
1083 
1084 		switch (protocol) {
1085 		default:
1086 			dev_dbg(&dev->dev, "%u:%d: unknown interface protocol %#02x, assuming v1\n",
1087 				iface_no, altno, protocol);
1088 			protocol = UAC_VERSION_1;
1089 			/* fall through */
1090 		case UAC_VERSION_1:
1091 			/* fall through */
1092 		case UAC_VERSION_2: {
1093 			int bm_quirk = 0;
1094 
1095 			/*
1096 			 * Blue Microphones workaround: The last altsetting is
1097 			 * identical with the previous one, except for a larger
1098 			 * packet size, but is actually a mislabeled two-channel
1099 			 * setting; ignore it.
1100 			 *
1101 			 * Part 1: prepare quirk flag
1102 			 */
1103 			if (altno == 2 && num == 3 &&
1104 			    fp && fp->altsetting == 1 && fp->channels == 1 &&
1105 			    fp->formats == SNDRV_PCM_FMTBIT_S16_LE &&
1106 			    protocol == UAC_VERSION_1 &&
1107 			    le16_to_cpu(get_endpoint(alts, 0)->wMaxPacketSize) ==
1108 							fp->maxpacksize * 2)
1109 				bm_quirk = 1;
1110 
1111 			fp = snd_usb_get_audioformat_uac12(chip, alts, protocol,
1112 							   iface_no, i, altno,
1113 							   stream, bm_quirk);
1114 			break;
1115 		}
1116 		case UAC_VERSION_3:
1117 			fp = snd_usb_get_audioformat_uac3(chip, alts,
1118 						iface_no, i, altno, stream);
1119 			break;
1120 		}
1121 
1122 		if (!fp)
1123 			continue;
1124 		else if (IS_ERR(fp))
1125 			return PTR_ERR(fp);
1126 
1127 		dev_dbg(&dev->dev, "%u:%d: add audio endpoint %#x\n", iface_no, altno, fp->endpoint);
1128 		err = snd_usb_add_audio_stream(chip, stream, fp);
1129 		if (err < 0) {
1130 			list_del(&fp->list); /* unlink for avoiding double-free */
1131 			kfree(fp->rate_table);
1132 			kfree(fp->chmap);
1133 			kfree(fp);
1134 			return err;
1135 		}
1136 		/* try to set the interface... */
1137 		usb_set_interface(chip->dev, iface_no, altno);
1138 		snd_usb_init_pitch(chip, iface_no, alts, fp);
1139 		snd_usb_init_sample_rate(chip, iface_no, alts, fp, fp->rate_max);
1140 	}
1141 	return 0;
1142 }
1143 
1144